Aurbach



Dec. 9, 1952 K. AURBACH LOCKABLE MACHINE KEY FOR BUSINESS MACHINES 4 Sheets-Sheet l Filed Aug. 16. 1949 alla \\\\\\\\\\\\\x l Inventor: fzzrZ /1 zzrach.

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Dec. 9, 1952 K.y AURBACH LOCKABLE: MACHINE KEY FOR BUSINESS MACHINES 4 Sheets-Sheet 2 Filed Aug. 16. 1949 y/////////////%AV ./o

Dec 9, 1952 K. AURBACH LOCKABLE MACHINE KEY FOR BUSINESS MACHINES 4 Sheets-Sheet 3 Filed Aug. 16. 1949 Inventor: KuZ'ZL/Iuraah.

De@ 9, 1952 K. AURBACH LOCKABLE MACHINE KEY FOR BUSINESS MACHINES Filed Aug. 16. 1949 4 Sheets-Sheet 4 mwm Inventor: Kuri/4111 acjz.

Patented Dec. 9, 1952 UNITED STATES PATENT OFFICE LOCKABLE MACHINE KEY FOR BUSINESS MACHINES Kurt Aurbach, Bielefeld, Germany, assigner to Anker-Werke, A. G., Bielefeld, Germany, a corporation of Germany Application August 16, 1949, Serial No. 116,554

4 Claims.

The invention relates to lockable machine keys for the key board oi business machines such as cash registers, calculating machines, accounting machines, or the like.

It is an object of the invention to obviate the necessity of providing special lockable manuals in addition to the amount, control or memo keys of the key board. An object of the invention is also to devise the normal depressable keys or push buttons of the key board so that any of them can be made latchable by a lock key. Another object of the invention is to provide a lockable business-machine key of an improved design and reduced dimensions as compared with the rather long or spacious designs of the lockable key devices heretofore available for similar purposes.

In order to achieve these objects, and in accordance with a feature of the invention, the head of a depressable machine key of the pushbutton type is hollow and encloses a lock, controllable by a removable lock key, for locking the machine key so as to prevent its actuation by an unauthorized operator. According to another feature of the invention, the key hole for the lock key is disposed at one side of the top face of the machine-key head and leaves an uninterrupted area on the top of the key head for an identifying numeral, letter or other character.

The foregoing and other objects and features of the invention will be understood from the following description in conjunction with the appertaining drawings.

Fig. 1 shows a cross-sectional side view of a machine key structure according to the invention, Fig. 2 a sectional top view of the same machine key along the sectional planes denoted in Fig. 1 by the line II-II, Fig. 3 a sectional View taken along the plane denoted in Fig. 2 by the line III-III, and Fig. 4 a section taken along the plane indicated in Fig. 2 by the line IV-IV, while Figs. 5 and 6 show a part-sectional side view and a top view respectively of a core piece appertaining to the same key structure.

Figs. 7 to 10 illustrate another embodiment of a lockable machine key according to the` invention, Figs. 7, 8 and 9 being views corresponding to those of respective Figs. 1, 2 and 3, while Fig. 10 shows a view of the key top surface.

The head portion of the lockable machine key structure shown in Figs. 1 to 6 comprises a sub.

stantially cupshaped housing l (Figs. 1 to 4) which contains a core piece 2 (Figs. 1 to 6). The core piece has a recess between two leg portions in which a shaft 3 (Figs. 1, 2, 4) is mounted.

The shaft carries a stack of individually revolvable lock tumblers 4. A leaf spring 5 (Fig. 1 and Fig. 4) is provided for each tumbler. Each tumbler has two latch projections 6 and a feeler projection l. A stop plate 8 has its lower end abut against a part 22 (Fig. 1) of the stationary machine structure when the machine key is mounted on the machine. The two latch projections 6 of each tumblei` 4 straddle the stop plate 8 when the machine key is unlocked so that then the machine key can be depressed, i. e. can move downwardly (in Fig. 1). When the machine key is locked, the tumblers deflect from the position shown in Fig. 1 so that then the projections B will abut against a stop surface 20 of plate 8 (Figs. 1, 4), thus preventing the ma chine key from being depressed. The projections 1 of the tumblers are engageable with recesses II of a lock key I2 (Fig. 1). The housing I also contains four plates I3 to I6 of which the plate I4 has a tongue Il (Figs. l, 2, 3) cut and bent out of the plate material. The stem I8 oi the machine key has a groove engaged by the tongue Il. The bottom of the key haed is covered by a base plate I9 which encloses the locking element and is equipped with two slots. The stem I8 passes through one of the slots. The stop plate 8 is guided in the other slot and is held against the base plate I9 by springs 9 disposed in respective bores Ill of the core piece 2.

The hollow head of the machine key is assembled with the appertaining key stem I8 by forcing the head over the stem so that the tongue Il snaps into the stem groove and thus firmly and permanently attaches the head to the stem.

The operation oi the above-described device is as follows.

When the proper lock key I2 is being inserted, it first forces the tumblers 4 to move clockwise (Fig. l) in opposition to the respective springs 5. As the lock key I2 advances, the tumblers drop into the recesses II of the lock key l2 under the bias of springs 5 so that all tumblers stay clear of the stop plate 8. Hence, when the lock key I 2 abuts against the cover plate I9, the whole machine key structure including the stem I8 can be depressed until the machine key, in the depressed position, is latched by the machine mechanism in the known manner.

If a lock key is inserted that does not match the lock tumblers, the tumblers will rst also yield clockwise, but one or several of them will then drop into the recesses of the lock key an insufficient or excessive amount depending upon the shape of the wrong lock key. Consequently,

the tumblers now assume diierent positions in which at least one of them has one of its latch DlOJ'eCtiOrls 6 abut against the stop surface 20 of the plate 8. Consequently, the machine key cannot be depressed unless the wrong lock key is replaced by the right one.

The design of the embodiment shown in Figs. 7 to 10 is to a large extent similar to that of the key structure according to Figs. 1 to 6. Therefore, those individual elements of the second embodiment that correspond to elements l to 26 of Figs. 1 to 6 are denoted by IGI to |20 respectively so that the foregoing description is in substance correspondingly applicable to the embodiment of Figs. 7 to 10. However, the following differences should be noted. Y

According to Figs. 7 to 10, the key hole 122 for the lock key i I2 is arranged not in the center but at one side of the key head. This has the advantage of providing a more convenient and large area on the key top surface for accommodating a numeral, letter or other character, for instance to identify a clerk or waiter, as exemplied at 123 in Fig. 16. Such keys are more easily identifiable than if the characters are interrupted by the key hole.

Different from the rst described embodiment is also the fastening of the key head to the key stem H8. According to the second embodiment,

the key stem i i8 has a swallow-tail end inserted into ya matching groove of the core piece |22 and secured to the core piece 162 and housing IBI by a fastening bolt I2l. In Fig. 7 the stationary part denoted by I2@ corresponds to the part denoted by 22 in Fig. 1.

The invention permits of 'various design modifications other than those specically described without departure from the essential objects and features and within the scope of the claims annexed hereto.

I claim;

1. A machine key for the key-board of business machines, comprising a hollow key head, a core piece disposed within said key head and having a recess, a shaft mounted on said core piece across said recess, spring-biased lock tumblers pivoted on said shaft in said recess, guide means for receiving a lock key Vto cooperate with said tumblers, a `stop plate guided in said Akey head and engageable with said tumblers, and springs mounted between core piece and-said stop plate for biasing said stop plate to a given position.

2. With a business machine having a fixed keyboard structure, the combination of a depressible machine key having a stem axially displaceable relative to said structure and having a hollow key head nrmly mounted on said stem to be displaceable together therewith, a stop member projecting out of said head and being abuttable against said structure `along the displacement path of said key, said stop member being movable relative to said head and having a biasing spring ending -to hold said part in projected position, and a lock mechanism disposed within said hollow head Vand having lock means movable into and out of latching engagement with said stop member to prevent movement-of said stop member relative to said head when said mechanism is in locked condition, said mechanism having a key hole on the side of said head opposite said stem, and a lock key insertable through said hole and operatively engageable with said mechanism, whereby said stop member when abutting against said structure can yield toward said head and permit depression of said machine key only When said mechanism is unlocked by means of said lock key.

3. A machine key for the key-board of business machines, comprising an axially displaceable key stem, a hollow key head iirmly mounted on said stem and displaceable therewith when operatively moved, a core piece disposed within said key head and rmly secured thereto, said core piece having a recess, locking means disposed within said head for locking the machine key in inactive position and having lock tumblers movably mounted on said core piece and guide means for a lock key to actuate said tumblers, and a stop plate projecting out of said head at the bottom side thereof so as to be abuttable against xed structure when said head is axially displaced, said stop plate being resiliently mounted on said head and engageable by said tumblers when said tumblers are in locking position, whereby said stop plate is capable of yielding into said head only when said tumblers are disengaged from said stop plate.

4. A machine key for the key-board of business machines, comprising an axially displaceable ykey stem, a hol-low key head iirmly mounted on said stem and displaceable therewith, said head having a housing oi an inverted cupshaped form so that its bottom forms the top surface of the machine key, a core piece disposed within said housing and having a recess, a lock mechanism `disposed `in said housing for locking the machine key in inactive position, said mechanism having lock tumblers movably mounted on said core piece Within said recess and guide means for a lock key to actuate said tumblers, a base plate covering said housing and being iirmly attached to said housing, a stop plate engageable by said tumblers when said tuinblers are in locking position, said stop plate mounted.

within said housing and extending through said base plate to the outside of said key head so as vto be abuttable against iixed structure when said head and stem are axially displaced, biasing spring means disposed in said housing and engaging said stop plate for holding it against said base plate so that said stop plate when abutting against said structure can yield for permitting the machine key to be Adepressed only when said tumblers are disengaged from said stop plate.

KURT AURBACH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Y Date 688,827 YCleal Dec. 17, 1901 824,841 Brandt July 3, `1906 982,417 Felt Jan. 24, 1911 986,329 Voight Mar. 7, 1911 2,167,620 Beaumont Aug. 1, l1939 2,210,562 Anderson Aug. 6, 1940 2,248,190 Pitman July 8, 1941 2,265,125 Beria Dec. 9, 1941 'FOREIGN PATENTS Number Country Date 138,065 Great Britain Jan. 20, 1921 206,467 yGreat Britain Nov. 9, 1923 

